Can canvassers from David Koch’s Tea Party group beat Democrats on the ground?

The soft-spoken voter explains why he’s sticking with Obama. The activists politely try to change his mind. “You might want to consider, if you’re on Medicare, that President Obama is taking $700 billion out of Medicare,” says Steve. Henry keeps talking, but he never budges. “Mitt Romney’s problems are not my problems,” he says. “I’m in the middle class.”

“So are we,” says Steve.

After 15 minutes, the Tea Partiers decide to wrap it up. Everybody shakes hands. Henry clearly was glad for the company, but he didn’t help AFP move the needle. We stick with the tablet’s map and explore Leesburg. It doesn’t get any better. One address is a dentist office, closed for the day. The other is an apartment behind a “no solicitation sign.” The next is another business that greets customers with a new-looking Obama-Biden sign.

“Who came up with this list?” sighs Eric.

Steve looks across the street from that pro-Obama business and sees another black voter, sitting on a stoop next to a pickup truck loaded with construction gear. “Do you live here?” The voter, who doesn’t remove his dark sunglasses, says he does. “OK, you’ll do,” says Steve.

Eric and I stand over to the side, and Gail and Steve conduct their interview. “This is Obama country,” says Eric, who sounds more bemused than annoyed. “We’re not going to find Romney voters out here.”

Gail and Steve are getting one-word answers and recording them dutifully. Obama’s job so far? Approve. His choice for president? Obama. His choice for U.S. Senate? Undecided. It’s not going great, but it’s going—and then the tablet goes blank.

“Out of battery,” says Gail.

It’s only been an hour and 10 minutes, and we’re done for the day. I ask whether we can find a cellphone store and plug the tablet into a BlackBerry charger. “I’m not going there,” says Steve. So the Tea Partiers say a polite goodbye to their last subject. “Do you have work? Good! You don’t meet enough people with steady work.” We head to an intersection where the AFP bus can pick us up.

Nobody’s particularly satisfied with the day’s labors. “I don’t feel like we moved the ball,” says Steve. We see other green-shirted activists crossing Leesburg’s pleasant streets. We miss the bus, Eric calls it, and we finally catch it. The driver wends through Leesburg, picking up three more groups of people. One group, beset by the same low-battery crisis, is killing time by touring a graveyard.

“They’re looking for Democrat voters!” jokes Eric.

The Tea Partiers swap stories of voter contact, angry dogs, people who shut the door on the first question, and a couple of people who actually listened. Steve’s in a contemplative mood. “If Obama gets back in,” he asks me, “what are the odds, you think, that he’s impeached?” I say it would be tough to convict him of “high crimes” or to get a two-thirds vote in the Senate to expel him. “Well, there’s been a number of decisions which required the Congress to be involved, and he went around it.”

The bus arrives back at headquarters. AFP staffers have brought in fresh ice to cool their iced tea and lemonade. Virginia volunteers are finishing up with the phones and chatting with each other planning the next visits. The Marylanders are comparing stories, trying to figure out whether they reached enough voters. Shortly after 3:30, they gather in the front room again for a head count.

“We’re heading back to the so-called free state of Maryland,” says Loffer, the grassroots director. “I hope you enjoyed our low taxes and economic freedom.”

The Marylanders head toward their bus. They pose for a group photo. They get back to work, on their phones. And on Sunday, AFP will announce that its volunteers made 400,000 phone calls.

Correction, Sept. 25, 2012: This article originally misattributed the quote “We need more ballast at the front!" to volunteer Adam Nicholson.